To improve the line reliability of multi-address communication from a multi- address communication slave station and to execute multi-address communication without the aid of the console of a master station from the multi-address communication slave station by executing multi-address communication in a conventional frequency arrangement as it is with a radio line without using a wire circuit connecting the multi-address slave station and the master station.

A line controller 16 for multi-way repeating is provided on a repeater station 1. A communication control part and a signal control part, which are conventionally installed in the master station 2, are installed in the controller 16. The repeater station 1 is accessed from the multi-address communication slave station 3 by the radio line so as to execute multi-address communication. Namely, multi-address communication is executed from the multi-address communication slave station 3 by setting the arranging condition of present silent frequencies f1 and f2 as presupposition. Thus, line regulation and line control, which are conventionally executed in the master station 2, are executed from the multi-address communication slave station 3, by sharing the radio frequency f1 which is conventionally used only between the master station 2 and the repeater station 1. Thus, a conventional operation condition is continued.